ESCRT-dependent STING degradation inhibits steady-state and cGAMP-induced signalling

Abstract

Stimulator of interferon genes (STING) is an intracellular sensor of cyclic di-nucleotides involved in the innate immune response against pathogen- or self-derived DNA. STING trafficking is tightly linked to its function, and its dysregulation can lead to disease. Here, we systematically characterize genes regulating STING trafficking and examine their impact on STING-mediated responses. Using proximity-ligation proteomics and genetic screens, we demonstrate that an endosomal sorting complex required for transport (ESCRT) complex containing HGS, VPS37A and UBAP1 promotes STING degradation, thereby terminating STING-mediated signaling. Mechanistically, STING oligomerization increases its ubiquitination by UBE2N, forming a platform for ESCRT recruitment at the endosome that terminates STING signaling via sorting in the lysosome. Finally, we show that expression of a UBAP1 mutant identified in patients with hereditary spastic paraplegia and associated with disrupted ESCRT function, increases steady-state STING-dependent type I IFN responses in healthy primary monocyte-derived dendritic cells and fibroblasts. Based on these findings, we propose that STING is subject to a tonic degradative flux and that the ESCRT complex acts as a homeostatic regulator of STING signaling.

Classification and functional characterization of regulators of intracellular STING trafficking identified by genome-wide optical pooled screening

“…STING has been shown to traffic to the recycling endosome and STING-containing vesicles originating from this compartment are then degraded in an ESCRTdependent manner [8][9][10] . Interestingly, in our proximity ligation proteomics, GO analysis showed enrichment of "Retrograde transport at the Trans-Golgi-Network" at 2 hours post STING stimulation 8 . Involvement of the GARP complex in STING trafficking opens the possibility that an endosome-to-Golgi recycling pathway could be present to recycle activated STING, analogous to Golgi to ER STING retrograde trafficking [15][16][17]19 .…”

“…In order to identify genes regulating STING trafficking, we previously performed flow-based CRISPR screens and proximity-ligation proteomics that led us to characterize ESCRT as a regulator of STING degradation at the endosome 8 . The screen used a terminal readout of STING degradation at the lysosome, but STING trafficking is a dynamic and multifaceted process that can be followed intracellularly via microscopy.…”

Identification of genes associated with the silk gland size using multi‐omics in silkworm (Bombyx mori)

“…The proteomics data were collected and analysed using TF software (Applied Biosystems, Waltham, MA, USA). The DEPs were detected at |log2 (fold change)| > 0 and p ‐value < 0.05 (Gentili et al, 2023). GO and KEGG function enrichment analysis use GoatTools version 0.6.5 and KOBAS version 2.1.1 software, respectively.…”

The 2023 Report on the Proteome from the HUPO Human Proteome Project

“…Proteomics has also advanced insights into COVID-19, ,, cardiovascular, , and neurological disorders, and diseases of the eye. New workflows are being developed for working with low-level ,,− and low-volume samples. , Network analysis continues to inform studies on disease-related pathways. − …”